Azalea Bark Scale Diagnostic Guide

Eriococcus azaleae

Discovered in 1881, the azalea bark scale, Eriococcus azaleas, is a prominent pest of rhododendron, azalea, and huckleberry (Vaccinium spp.). It has been reported in the Eastern US, as well as Belgium and Russia. This is a pest that generally does not kill hosts, rather it causes aesthetic damage. Honeydew can be an inconvenience as well.

Treatment Strategy

Nymphs must be targeted when they are unprotected by the waxy covering. This means dormant horticultural oil sprays may be used after the growing season is complete. A more effective option is to apply a systemic insecticide either during the prior fall or spring to control feeding crawlers from the inside of the plant.

Soil Application using Xytect 75WSP 22 packets

Treatment Expectations

Management of this pest is easiest when the nymph stage is targeted. Soil applied systemics have made application timing and methods much easier.

A Diagnostic Guide is designed to help you identify a pest issue and management solutions. Always refer to product label for all rates and approved uses. Some images courtesy forestryimages.org. Use of the images does not imply endorsement of treatments by forestryimages.org